Lamp



1940. c. c. MATERA 2,213,012

LAMP v Filed Feb. 23, 1958 Patented Aug. 27, 1940 UNITED srAss ATNTOFFICE LAMP v Application February 23, 1938, Serial No. 191,995

3 Claims.

-My invention relates more particularly to that class of lamps which areprovided with means for directing the light rays in a manner to avoidglare, as in the use of headlights for vehicles, although the inventionis not limited to such uses, and an object of my invention, amongothers, is the production of a lamp of this type having means for sodirecting the light rays that the intensity of such rays and theobjectionable glare produced thereby shall be eliminated in certainlocalities relatively to the source of the rays, while at the same timeproducing sufficient illumination for all practical purposes in otherlocalities which the lamp is employed to light. One form of a lampembodying my invention and in the construction and use of which theobjects herein set out, as well as others, may be attained isillustrated in the accompanying drawing in which- Figure 1 is a view infront elevation of a lamp embodying my invention.

Figure 2 is a view in central vertical section through the lamp.

Figure 3 is a similar view but illustrating a modified form of theinvention.

Figure 4 is a view on enlarged scale illustrating the disposition of thefilament.

Figure 5 is a view of a fragment of the reflector illustrating amodified form of the invention.

Figure 6 is a detail view of a fragment of the rim illustrating amodified form of my invention;

Figure 7 is a similar view but showing a fragment at the inner end ofthe reflector.

I have learned from long experience and repeated demonstration that theobjectionable glare produced by headlights having reflectors ofparabolic or similar shape, and which are of the more desirable type, isprincipally due to the fact 1 that a large portion of the rays boundingfrom the reflecting surface at the sides of the light source andadjacent a horizontal plane passing through the focal axis of thereflector are proedges and uncurved crosswise.

(Cl. Mil-41.35)

zontal plane passing through the focal axes of the reflectors when thevehicles are traveling on the same plane. It is of course essential thatthe light rays shall not be diverted to an extent to impair theillumination by the lamp to a degree to destroy its efliciency forlighting purposes, but I have also found that the light rays produced bythe most common type of reflectors and which project in lines parallelwith the axes of the reflectors may be reduced to a considerable 10extent, thereby decreasing the glare without 0bjectionably lessening thelighting efficiency of the lamp. This my improved lamp is illustrated inthe drawing herein in which the numeral 5 denotes the shell of the lampthat may be of any 15 suitable shape and composed of any desiredmasupported by an adjusting screw 9 and upon a spring ill. The front ofthe shell is closed by a glass ll. 7

The reflector is mounted in the shell, being supported at the edge ofthe shell adjacent the glass M. This reflector comprises an upperreflecting member l2 and a lower reflecting member 13. The focal centersof these two reflectors are located in the focal axis of the lamp but onopposite sides of the source of light, or filament '1, the focal pointof the reflector I2 being back of the filament at the point denoted bythe numeral l4 and the focal point of the reflector I3 being located infront of the filament at the point denoted by the numeral l5.

Two secondary reflectors l6 and IT are, located on opposite sides of ahorizontal plane passing through the focal axis of the lamp, thesereflectors being in the form of bands with parallel These bands areinclined relatively to the horizontal plane hereinbefore referred to andat an acute angle relatively to said plane, said bands extendingforwardly from a point just back of the point of illumination. The angleof the band 16 with respect to said plane is more acute than that of theband ll, as shown in Fig. 2 of the drawing. This disposition of the-twosecondary reflectors is such that all rays from the source of light willeither directly or eventually by reflection be projected downwardlybelow said focal plane and the glare heretofore caused from this area inthe reflector is removed from objectionable zones and is projected intoareas on the ground where its effects will be beneficial.

= My experiments have further demonstrated that the disposition of thefilament affects the glare to an appreciable extent. I propose to use abulb in which the glowing portion of the filament extends in an axialplane and to position this horizontally so that a minimum number of rayswill be projected above the horizontal focal plane hereinbefore referredto, this number being so small as to be unobjectionable. The vastmajority of the number of rays will be confined to an area extending nothigher than said horizontal plane and the glare above such plane to anunobjectionable extent is avoided. This arrangement is shown in Fig. 1of the drawing in which the glowing portion [8 of the filament is shownas disposed horizontally and across the focal axis of the lamp.

That form of the device shown in Fig. 3 is similar to that hereinbeforedescribed except that the upper reflector I9 is extended below thehorizontal axial plane of the lamp to the opposite edge where it issecured. The lower refleeting member 29 is formed of a separate piece ofmaterial spaced from the extension 2i just described and as shown inFig. 3 of the drawing. This reflector 2G is in substantially the sameposition as that occupied by the reflector !3 shown in Fig. 2. Otherwisethe structure shown in Fig. 3 is substantially like that shown in Fig.2.

As hereinbefore explained a material feature of my invention consists inarranging the filament to extend horizontally, and in combination withthis feature I have found that the band hereinbefore referred to andextending along the reflector on opposite sides a horizontal planepassing through the axis of the reflector may be variously constructed.This is accomplished in one instance by the angular disposition of thedifferent portions of the band as hereinbefore referred to. This purposemay be accomplished also by rendering this band nonreflective asillustrated in Fig. 5, and with this in mind the invention may beembodied in a structure with a reflector arranged as shown in Fig. 5 orin a structure in which the reflector is composed of two sections asillustrated in Figs. 2 and 3 of the drawing.

A satisfactory manner of rendering the band 22 non-reflective is bymaking it black as shown in Fig. 5, but any other means may be employedfor accomplishing this purpose.

In that form of reflector illustrated in Figs. 6 and 7 the structure isthe same as that hereinbcfore described with the exception that the bandbetween the two main reflectors is disposed at a single angle withrespect to the horizontal plane hereinbefore referred to, said bandextending across said horizontal plane, and it is observed that thisband may be reflecting or non-reflecting as hereinbefore mentioned.

I also contemplate as within the spirit and intent of my invention thatthe members comprising the band at the intersection of the two mainreflectors need not necessarily consist of two members but that agreater number may be employed if desired, and it is also not absolutelyessential that the angle between the two members of this band benecessarily limited in the horizontal plane hereinbefore referred to.

I claim:

1. A lamp comprising an upper and a lower reflector each ofsubstantially parabolic shape and positioned to locate their focalcenters one in advance of the other, a source of light located betweensaid focal centers in the axis of the lamp, and a reflecting bandlocated between said rcflectors and extending across a horizontal planepassing through said axis and comprising two in .nbers angular-1ydisposed on each side of and with the angle between them coincident withsaid horizontal plane to project the rays on op pcsite sides of saidplane downwardly below said 1138.118

2. A lamp comprising an upper and a lower reflector each ofsubstantially parabolic shape ani positioned to locate their focalcenters one in dvance of the other, a source of light 10- between saidfocal centers in the axis of the .amp, and a reflecting band locatedbetween said reflectors with its upper edge offset at an angle from theupper reflector and extending across a horizontal plane passing throughsuch and comprising two members angularly disposed on each side of andwith the angle between them coincident with said horizonal plane toproject the rays on opposite sides of said plane downwardly.

3. A lamp comprising an upper and a lower reflector each ofsubstantially parabolic shape and positioned to locate their focalcenters one in advance of the other, a source of light located betweensaid focal centers in the axis of the lamp, and a reflecting bandlocated between said reflectors and extending across a horizontal planepassing through said axis, said reflecting band having its upper edgeoffset at an angle from the upper reflector and then extendingbackwardly at an angle and then forwardly at an angle, said lastmentioned angle being coincident with said horizontal plane to projectthe light rays on opposite sides of said plane downwardly.

CHARLES C. MATERA.

